Typically, electronic packages of the type mentioned above include a circuitized substrate (e.g., printed circuit board) and a semiconductor device (chip) electrically coupled thereto. Several examples of these are known in the art including those defined in U.S. Pat. Nos. 4,849,856 (Funari et al), 4,914,551 (Anschel et al), 4,326,238 (Takeda et al), 4,698,662 (Young et al), 4,729,061 (Brown) and 5,012,386 (McShane). Understandably, a major factor in the successful operation of such packages involves effective heat removal from the package, and particularly the semiconductor device(s) utilized as part thereof. Such heat removal may be accomplished using a heat sink structure such as the type defined in the aforementioned U.S. Pat. Nos. 4,849,856 and 4,914,551. As defined therein, the semiconductor device is thermally coupled to these heat sink members such that the heat generated by the device passes thereto for eventual dissipation into the ambient surrounding the package.
In a more recent version of such package structures, the package substrate includes a relatively thick thermal and electrically conductive (e.g., copper) layer having thereon a dielectric material (e.g., fiberglass reinforced epoxy resin) which in turn includes a desired circuitization layer (e.g., copper) thereon. Such a structure is defined in co-pending application Ser. No. (S.N.) 07/598,466, entitled, "Electrical And/Or Thermal Interconnections And Methods For Obtaining Such", filed Oct. 09, 1990. This application is incorporated herein by reference. As defined in Ser. No. 07/598,466, various apertures are provided within the structure to promote heat transference from the operating semiconductor device to the thickened copper layer located thereunder, these apertures, in one embodiment, including a quantity of conductive material (e.g., copper) plated along the surfaces thereof or, in another embodiment, including solder or the like within the aperture. In both instances, heat generated from the semiconductor device passes to an adjacent heat spreader or the like and then into the thermally conductive apertures, which apertures extend within or through the thick copper layer. Understandably, this thick copper layer functions as a heat sink for the package.
In accordance with the teachings herein, the present invention provides an improved heat sinking package over the embodiments defined in Ser. No. 07/598,466 by eliminating the need for apertures or the like within the structure, while still assuring greater heat dissipation for the final package.
It is believed that such an electronic package would constitute a significant advancement in the art.